1. Field of the Invention
The present invention relates to a headphone. More particularly, the present invention relates to a headphone having a belt-like member which is drawn out when the headphone is put on the head.
2. Background of the Invention
In order to obtain the optimum reproduced sound and acoustic effects, it is required of a headphone that the headphone units fit over the ears of the user in the most suitable position. For this reason, in the past, various headphones equipped with adjusting mechanisms with which it is possible freely to adjust the position of the headphone units to suit the size and shape of the user's head and the position of the ears have been proposed.
The present applicant proposed the kind of headphone shown in U.S. Pat. No. 5,018,599. The construction of that headphone will now be explained using FIGS. 1 through 4.
In this headphone, as shown in FIGS. 1 and 2, a pair of headphone units 4 are pivotally mounted on the two ends of an inverted U-shaped headband 1 by way of support members 2 and support arms 3.
The headband 1 includes a plate-like member, having elasticity, formed into an inverted U-shape. It is necessary that the headband be elastic in this way in order that when the headphones are fitted onto the head the headphone units 4 mounted on the ends of the headband 1 are pressed against the ears with a fixed side pressure.
The headband 1, as shown in FIG. 2, is a generally inward-facing flat member, C-shaped in cross-section, and its open side is covered by a cover member 6. A space 7 is provided inside this headband 1. A spring member 9, which links the two ends of a belt-like suspender 8 which will be discussed hereinafter, is accommodated in this space 7.
Support members 2, 2 are mounted on the ends of the headband 1. These support members 2 pivotally support the support arms 3 by means of support shafts 10, and hold the headphone units 4 which are fitted to the support arms 3.
These support members 2 each have an outer part 12 and an inner-side plate 13 so that, like the headband 1, a space 11 is provided inside them. The inner-side plates 13 are each provided with an opening 14.
A suspender 8 is fitted to the headband 1 constructed as described above, as shown in FIG. 1. That is, the two ends of the suspender 8 are respectively drawn into the headband 1 through the openings 14, 14 in the support members 2, 2 mounted on the two ends of the headband 1 and are linked together by the spring member 9. The suspender 8 is strung across in such a way that the middle portion of the suspender 8 becomes, as a head-support portion 15, like a bowstring on the inward side with respect to the headband 1.
When the headphone is fitted onto the user's head, this suspender 8 supports the head by fitting around the head. When the headband 1 is fitted onto the user's head, the headband 1 is spread out and the head-support portion 15 of the suspender 8 is drawn out from inside the headband 1 against the pulling force of the spring member 9. By the suspender 8 fitting around the head along the contour of the head, the head is pressed upon and supported by the suspender 8.
The spring member 9 at all times pulls-urges the suspender 8 toward the inside of the headband 1. The spring member 9 is for providing the suspender 8, which is drawn out when the headphone is fitted onto the head, with a fixed tension. In order that it exert the same pulling force on both ends of the suspender 8, the central portion of the spring member 9 is fixed to the inside of the top of the headband 1.
The headphone units 4, as shown in FIG. 2, each have a housing part 16, made from natural wood, and a speaker unit 17. Each housing part 16 includes a front side, to the central portion of which the speaker unit 17 is fitted, and a rear side. A sound absorbing material is accommodated inside the housing part 16. Multiple sound radiating holes are provided in the front side of the housing part 16.
These headphone units 4 are fitted to the ends of the headband 1 in the following way:
The headphone units 4 are fitted to the support members 2 on the ends of the headband 1 by way of the support arms 3.
The support arms 3 are pivotally mounted on the support members 2 by way of the support shafts 10. These support arms 3 each have circular arc-form arms 3a, 3b which extend with the support shaft 10 as their base end. A housing support member 22 is fitted to the ends of these arms 3a, 3b.
This housing support member 22 is of circular-arc form. Three concave portions 23 are provided on the inner periphery of the housing support member 22, and a cutaway portion 24 is provided in the center of each of these concave portions 23. A buffer grommet 25 is fitted in each of these cutaway portions 24. The housing part 16 is fixed to this housing support member 22 at three points by fixing screws 26 which pass through these buffer grommets 25.
The buffer grommets 25 are made of an elastic material such as plastic. A through hole is provided in the axial-direction central portion of each of the buffer grommets 25. These through holes are for allowing the fixing screws 26 to pass through. The support portions of the buffer grommets 25 are fitted into the cutaway portions 24 and the fixing screws 26 are passed through the buffer grommets 25 and screwed into screw holes 28 provided in the front side of the housing part 16. As a result, the headphone unit 4 is supported by the housing support member 22. Consequently, by means of the elastic deflection force of the buffer grommets 25, non-alignment of the screw holes 28 with the cutaway portions 24 of the housing support members 22, caused by shrinkage in the housing part 16, can be tolerated.
Ear pads 29 are fitted in such a way as to cover the front sides of the housing support members 22 which support the headphone units 4, and make the headphone set more comfortable to wear.
However, in the case of the headphone shown in FIGS. 1 through 4, it is necessary for the spring member 9 to be built into the inside of the headband 1. For this reason, it becomes necessary for the headband 1 to be made up of two or more members. Also, it is necessary for the suspender 8 to be passed through the insides of the headband 1 and the support members 2 after being linked to the spring member 9, and the assembly work has been complicated. And, because the number of parts in the headphones is increased, there has been the danger of the weight of the headphones increasing. Furthermore, because the spring member 9 is built into the headband 1, the width and the thickness of the headband 1 have been large. As a result of this, in the design of the headphones, building the spring member into the headband has placed limitations on the headphone design.